Opensearch Springboot : ElasticsearchDataConfiguration$ReactiveRestClientConfiguration Exception

Question

I am trying to start the demo app for creating some index and doing some operations. But stumbling on this error -

    024-03-16T12:39:25.867+05:30 ERROR 9085 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataConfiguration$ReactiveRestClientConfiguration': Lookup method resolution failed

This is my pom -

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example.elasticsearch</groupId>
    <artifactId>elasticsearch-poc</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>elasticsearch-poc</name>
    <description>Demo project for Spring Boot ElasticSearch</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test-autoconfigure</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.opensearch.client</groupId>
            <artifactId>spring-data-opensearch-starter</artifactId>
            <version>1.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.opensearch.client</groupId>
            <artifactId>spring-data-opensearch-test-autoconfigure</artifactId>
            <version>1.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.opensearch.client</groupId>
            <artifactId>opensearch-rest-high-level-client</artifactId>
            <version>2.12.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Code for creating the index -

package com.example.elasticsearch.elasticsearchpoc;

import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.opensearch.client.RequestOptions;
import org.opensearch.client.RestClient;
import org.opensearch.client.RestClientBuilder;
import org.opensearch.client.RestHighLevelClient;
import org.opensearch.client.indices.CreateIndexRequest;
import org.opensearch.client.indices.CreateIndexResponse;
import org.opensearch.common.settings.Settings;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration;

import java.io.IOException;
import java.util.HashMap;

@SpringBootApplication(exclude = {ElasticsearchRepositoriesAutoConfiguration.class})
public class ElasticsearchPocApplication {

    public static void main(String[] args) throws IOException {

        SpringApplication.run(ElasticsearchPocApplication.class, args);

        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();

        credentialsProvider.setCredentials(AuthScope.ANY,
                new UsernamePasswordCredentials("admin", "admin"));
         //Create a client.
        RestClientBuilder builder = RestClient.builder(new HttpHost("localhost", 9200, "http"))
                .setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
                    @Override
                    public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
                        return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
                    }
                });
        RestHighLevelClient client = new RestHighLevelClient(builder);

        //Create a non-default index with custom settings and mappings.
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("custom-index");

        createIndexRequest.settings(Settings.builder() //Specify in the settings how many shards you want in the index.
                .put("index.number_of_shards", 4)
                .put("index.number_of_replicas", 3)
        );
        //Create a set of maps for the index's mappings.
        HashMap<String, String> typeMapping = new HashMap<String,String>();
        typeMapping.put("type", "integer");
        HashMap<String, Object> ageMapping = new HashMap<String, Object>();
        ageMapping.put("age", typeMapping);
        HashMap<String, Object> mapping = new HashMap<String, Object>();
        mapping.put("properties", ageMapping);
        createIndexRequest.mapping(mapping);
        CreateIndexResponse createIndexResponse = client.indices().create(createIndexRequest, RequestOptions.DEFAULT);

    }

}

---

Question 1 - Why the error? what does it mean?

Question 2 - I am starting open search 1.2 in local using docker. Is it compatible with open search high rest client 2.12.0 + spring-data-opensearch 1.3 + spring boot 3 ? (we are trying to upgrade our clients to spring boot 3 and migrating to open search from elastic search clients 7. It is not possible to update the server from 1.2)

Answer 1

This was happening due to wrong exclude class I have mentioned in Application class.

According to docs -

https://github.com/opensearch-project/spring-data-opensearch?tab=readme-ov-file

We have to exclude

@SpringBootApplication(exclude = {ElasticsearchDataAutoConfiguration.class})

the ElasticsearchDataAutoConfiguration configuration from automatic discovery (otherwise, the Elasticsearch related initialization kicks in, see please spring-projects/spring-boot#33010)